1. Field of the Invention:
This invention relates to an in-line connector for mating straight terminal tails of a connector to a printed circuit board (PCB) and more particularly in a preferred embodiment to an in-line connector for a PCB wherein the terminals mounted in a plastic header are fixedly attached to the PCB and are not disturbed by stress from extremely high temperature transitions even though the plastic materials of the header may expand at a greater rate than the metal alloy terminals.
2. Description of the Prior Art:
Most PCB connectors that have plastic headers include structure that provides for stress between the header and the tails of the terminals that attach to the PCB. These connectors usually employ bent terminals that allow for extension of terminal length in proportion to the thermal expansion of the plastic header material. U.S. Pat. No. 4,491,376 dated Jan. 1, 1985 of Gladd et al. describes one such header.
There, a header assembly comprises a thermoplastic housing and several rows of metallic terminals that attach to a PCB. The terminals have tails which bend over anvil portions of the housing and project through slots in a locator plate at the conductor end of the housing. The locator plate slots have detents for retaining the bent tails in a pattern to facilitate assembly and soldering of the tails in a matching pattern of PCB holes. Flexure of the terminals in enlarged rearward cavity portions and slippage of the bent tails in the detent reduces stress on the solder connections due to differential thermal expansion. This form of connector appears to form a suitable right-angled header since the angled surfaces of the header cooperate effectively with the flexing of the terminals to remove the stress.
U.S. Pat. No. 4,802,860 dated Feb. 7, 1989 of Kikuta discloses another right-angled header. There, the connector has an insulated housing with a plurality of contact receiving apertures and a plurality of contacts, each contact having a front section, an intermediate section and a rear section. The rear section of the contact is placed in a chamber which permits movement of the contact for absorbing thermal stresses placed on the union of the contacts and the PCB. The contacts have bent regions to compensate for the expansion. Again, bent terminals permit terminal flexure during periods of thermal expansion of header material when subjecting the connector and board to excessive thermal conditions.
Straight terminal connectors have been utilized for PCB attachment primarily under environmental conditions that permit such use. The metallic terminals and the plastic headers experience no extreme transitions of thermal conditions.
In circumstances where extreme thermal conditions exist, bent terminals have been employed to permit flexure of the terminals in order to preserve the integrity of the terminal/wire-run fixed joint.